Sarah Brown to publish a 'very personal' memoir in six-figure deal

Sarah Brown is set to spill the beans about her life as the wife of Gordon Brown in a new book

Sarah Brown has become the latest high-profile political figure to cash in on her time at the heart of power after signing a lucrative book deal.

Gordon Brown's wife today confirmed that she is writing a 'very personal' memoir, which publishing insiders say is worth six figures.

But insiders have described Mrs Brown’s recollections as disappointing and she is understood to have had trouble finding interest in the book.

HarperCollins, which is publishing Lord Mandelson’s diaries this summer, is among leading publishers believed to have rejected it.

The former Prime Minister's wife memoirs, entitled Behind The Black Door, will be published on Mother's Day next year by Ebury Press.

Mrs Brown is believed to have kept a diary for several years detailing her account of life at the centre of affairs while her husband was at No10 and No11.

Her insight on Mr Brown's notoriously turbulent relationship with the former Prime Minister Tony Blair could make explosive reading.

Mrs Brown today broke the news of her new book deal to her 1.2million followers on the social networking site Twitter.

The former PR executive said: 'Just agreed with my publisher Ebury to write a book - working title "Behind the Black Door" - so chained to laptop from Monday morning,' she wrote.

Some were quick to warn Mrs Brown that her title may need changing as it is the same as a 1987 porn film directed by Ron Jeremy.

Mrs Brown lived in Downing Street for nearly a decade after marrying the then Labour Chancellor in 2000, and the couple brought up their two young sons John and Fraser there.

Gordon and Sarah Brown left 10 Downing Street for the last time in May. Insiders have described her recollections as disappointing

She eschewed her life in public relations to become a full-time charity campaigner and is now president of the charity Piggy Bank Kids and patron of Women's Aid and Maggie's Cancer Caring Centres, among others.

The former PM's wife will speak about experiences such as shopping with armed police protection and 'coping with a bad hair day when Carla Bruni's in town'.

By publishing her memoirs, Mrs Brown is following in the footsteps of other senior Labour figures such as Lord Mandelson, Tony Blair and Alastair Campbell in rushing out their memoirs following the party's General Election defeat.

Lord Mandelson has promised his tell-all memoirs will expose the 'soap opera' years of New Labour and will 'ruffle feathers'.

His account of his time at the heart of the New Labour and his ringside seat on the notorious feuds between Mr Blair and Gordon Brown is being tipped by friends as 'explosive' reading.

Meanwhile, Mr Blair's The Journey is being published by Random House on September 2.

The unedifying spectacle of senior Labour figures rushing to print their memoirs within months of the party's general election defeat has prompted accusations of hypocrisy as they have been scathing of senior civil servants doing the same.

A spokesman for Ebury did not disclose whether Mrs Brown will donate the proceeds from her book to charity.